Director Service Agreement & Independent Contractor Agreement

I am a director for an OPC company as well as a full shareholder. Do I need a Director\'s service agreement. My client in the US will decide the amount to be paid for the contractors I am hiring in India. If let\'s say he is agreeing for $7/hr. How do I mention that in the contractor agreement as I think all the agreement and payment should be mentioned in Indian rupees. Can I say the following \"The payment will be transferred to Contractor bank account in Indian Rupees(INR) (Final transaction amount will vary based on USD to INR conversion rate during the transaction period)